syms a k w x n z
f1 = n^3;  
ZF1 = ztrans(f) 
f2 = a^z;
ZF2 = ztrans(g) 
f3 =cos(a*n);
ZF3 = ztrans(f,w) 
f4 = exp(k*n^2)*sin(k*n);
ZF4 = ztrans(f,k,x)
